Acute Ataxia in Children: A Review of the Differential Diagnosis and Evaluation in the Emergency Department

Etiologies and clinical characteristics of acute ataxia in a single national children's medical center

OBJECTIVE

To analyze etiologic factors of pediatric acute ataxia and to identify the severity of its underlying causes for urgent medical intervention.

METHODS

Clinical data of children diagnosed with acute ataxia between December 2015 and December 2021 from one national medical center were analyzed retrospectively.

RESULTS

A total of 99 children (59 boys, 40 girls), median age at disease onset 55 (range: 12-168) months, were enrolled. The median follow period was 46 (range 6-78) months. Eighty-six (86.9 %) children were diagnosed with immune-associated acute ataxia, among which acute post-infectious cerebellar ataxia (APCA) was the most common diagnosis (50.5 %), followed by demyelinating diseases of the central nervous system (18.2 %) and Guillain-Barré syndrome (9.1 %). On cerebrospinal fluid (CSF) examination, 35/73 (47.9 %) patients had pleocytosis (>5 cells/mm3), and 18/73 (24.7 %) had elevated protein levels. Thirty-one patients (31.3 %) had an abnormal cerebral MRI. Children with other immune-associated acute cerebellar ataxia had more extracerebellar symptoms, intracranial MRI lesions, abnormal CSF results, longer hospital stay, higher recurrence rates and incidence of neurological sequelae than children with APCA.

CONCLUSION

Immune-associated acute ataxia is the main cause of pediatric acute ataxia, among which APCA is the most common phenotype. However, some immune-associated diseases, especially autoantibody-mediated disease, which has a higher recurrence rate and neurological sequelae account for an increasing proportion of pediatric acute ataxia. When children present with extracerebellar symptoms, abnormal cranial MRI or CSF results, and without prodromal infection, prudent differential diagnosis is recommended.

"The Red Flags" in Clinical Approach to Acute Ataxia-the Experience in Cohort of 76 Children

The aim of our study is to define the most frequent etiology, clinical presentation, and predictive factors of outcome in children with acute ataxia (AA) and to determine "the red flags" in the diagnostic approach to children with AA. The retrospective study included the patients with AA treated in the institute from 2015 to 2021. The inclusion criteria were children aged 1-18 years, evolution time of ataxia within 72 h, and diagnosis made by a physician. The exclusion criteria were anamnestic data about ataxia without confirmation by any physician, chronic/persistent ataxia, and psychogenic or postictal ataxia. Clinical presentation was divided into two categories: (1) isolated cerebellar signs (CS): ataxic gait, dysmetria, dysdiadochokinesia, intention tremor, dysarthria, and nystagmus; (2) CS-plus symptoms which included CS associated with any of other symptoms such as encephalopathy (GCS < 15), awareness disturbances, vomiting, headache, a new onset limb or facial paresis, torticollis, hypotonia, and opsoclonus. The outcome was assessed at the end of hospitalization and was defined as complete or incomplete recovery. The study included 76 children, with a mean age of 5.7 years (IQR 2.1-8.3). The most frequent causes of AA were immune-mediated/infective cerebellar ataxia in 27 (35.5%), and intoxication in 24 (31.6%) cases, followed by vestibular ataxia, opsoclonus-myoclonus-ataxia syndrome, and intracranial expansive process. Forty-two (56%) cases experienced isolated CS, and 35 (46%) cases had CS-plus. Complete recovery was experienced by 62 (81.6%) patients. Analysis of some risk factors (sex, age, presence of previous infection, "cerebellar plus symptoms," and structural abnormalities/neuroimaging abnormalities) and their relation to outcome was performed. Analysis showed that presence of additional symptoms to ataxia, so called "cerebellar plus symptoms" (p = 0.002) and structural abnormalities (p < 0.001), had statistically higher frequency of poor outcome. Statistical significance remained in the univariate analysis. Significant data was included in multivariate logistic regression analysis which also showed that presence of "cerebellar plus symptoms" (p = 0.021) and structural abnormalities (p = 0.002) is related to a poor outcome. Most of the children with AA have "benign" etiology such as intoxication and post/parainfectious cerebellar ataxia with favorable outcomes. On the other hand, AA might be the first manifestation of CNS neoplasm or paraneoplastic phenomena. "The red flags" associated with cerebellar signs are limbs or facial palsy, hypotonia, GCS < 15, vomiting, opsoclonus, headache, myoclonus, visual impairment, torticollis, and vertigo. The presence of those signs and/or structural brain abnormalities was related to poor outcomes in children with AA.

Post-Infectious Acute Cerebellar Ataxia Treatment, a Case Report and Review of Literature

Background: infectious mononucleosis is very common during childhood and neurological manifestations are extremely rare. However, when they occur, an appropriate treatment must be undertaken to reduce morbidity and mortality as well as to ensure appropriate management. Methods: we describe the clinical and neurological records of a female patient with post-EBV acute cerebellar ataxia, whose symptoms rapidly resolved with intravenous immunoglobulin therapy. Afterwards, we compared our results with published data. Results: we reported the case of an adolescent female with a 5-day history of sudden asthenia, vomiting, dizziness, and dehydration, with a positive monospot test and hypertransaminasemia. In the following days, she developed acute ataxia, drowsiness, vertigo, and nystagmus with a positive EBV IgM titer, confirming acute infectious mononucleosis. The patient was clinically diagnosed with EBV-associated acute cerebellitis. A brain MRI showed no acute changes and a CT scan showed hepatosplenomegaly. She started therapy with acyclovir and dexamethasone. After a few days, because of her condition’s deterioration, she received intravenous immunoglobulin and demonstrated a good clinical response. Conclusions: although there are no consensus guidelines for the treatment of post-infectious acute cerebellar ataxia, early intervention with intravenous immunoglobulin might prevent adverse outcomes, especially in cases that do not respond to high-dose steroid therapy.

Increasing Seizures, Encephalopathy, and Hypothermia in an 18-Year-Old Woman

ABSTRACT

An 18-year-old woman with a history of focal epilepsy presents with increasingly frequent seizures, encephalopathy, multiple laboratory abnormalities, and hypothermia. During her hospital course, her symptoms waxed and waned. Multiple etiologies of her symptoms were considered, but the spontaneous resolution of her symptoms and an abnormal MRI of the brain revealed the final diagnosis.

Evaluation of Acute Ataxia in the Pediatric Emergency Department: Etiologies and Red Flags

BACKGROUND

We aimed to evaluate patients with acute ataxia and to determine the warning clinical factors in the early prediction of neurological emergencies.

METHOD

Patients with a history of balance and gait coordination disorder and clinically diagnosed as acute ataxia in pediatric emergency department were included in the study. As a result of final diagnosis, the characteristics of patients with and without clinically urgent neurological pathology (CUNP) were compared. CUNP was defined as any nervous system disorder requiring early diagnosis and prompt medical or surgical treatment and/or intensive care unit admission to prevent disabling or life-threatening evolution.

RESULTS

Eighty-eight patients with a median age of 5 years were included in the study (37 [42%] patients with CUNP and 51 [58%] without CUNP). In the CUNP group, the median age of patients and symptom duration were significantly higher (P < 0.001 and P = 0.011, respectively). The most common etiologies were acute post/parainfectious cerebellar ataxias (n = 40 [45.4%]), acute cerebellitis (n = 9 [10.2%]), and Guillain-Barré syndrome (n = 8 [9%]). Hyporeflexia/areflexia and dysmetria were associated with a higher risk of CUNP. Headache, loss of consciousness, and visual dysfunction were the findings appearing exclusively in patients with CUNP.

CONCLUSIONS

The most common etiologies in acute ataxia are benign and transient, whereas life-threatening conditions may occur rarely and may require urgent intervention. Older age; prolonged symptom duration; focal neurological deficits such as hemiparesis, hyporeflexia, and visual impairment; and nonspecific findings such as loss of consciousness and headache are the most striking "red flags" of a potential neurological emergency and should alert clinicians to CUNP.

Clinical and Brain Imaging Findings of Children with Acute Ataxia: Ten Years of Experience at a Major Pediatric Referral Center

Background: Ataxia is a symptom of a wide range of disorders, which manifests as a lack of coordinated movements. It is commonly associated with cerebellar disorders. Objectives: To evaluate the neuroimaging findings of children with acute ataxia (AA) and to identify the association between these findings and clinical results. Patients and Methods: This cross-sectional study was conducted using the electronic medical records of patients, presenting to a major pediatric referral center over 10 years from March 2009 to February 2020. Patients were included in the study if they were younger than 18 years, were diagnosed with AA (< 30 days), and underwent magnetic resonance imaging (MRI), computed tomography (CT) scan, or both. The exclusion criteria were as follows: A history of neurological or medical disorders, explaining ataxia; pseudo-ataxia; a traumatic brain injury; severe loss of consciousness; and missing key information in the medical records (e.g., no brain imaging findings). Patient data, including the demographic data, clinical history, laboratory findings, imaging results, and in-hospital outcomes, were collected. A P-value less than 0.05 was considered statistically significant, and the confidence interval was set at 95%. Results: A total of 119 patients were included in this study (51% female; mean age, 4.9 years). Clinically urgent neurological pathology (CUNP) was detected in 37 (31.09%) patients. The most common pathologies on images were tumors, acute disseminated encephalomyelitis (ADEM), and stroke. However, the most common diagnosis was acute post-infectious cerebellar ataxia (APCA) (24.4%), followed by brain tumors (16.8%) and Guillain-Barre syndrome (GBS) (15.1%), respectively. Overall, 11 variables were significantly different between patients with and without CUNP. Most notably, the duration of symptoms (P < 0.01), ophthalmoplegia (odds ratio [OR] = 13.93; 95% confidence interval [CI]: 3.5 - 54.7), focal neurologic deficit (OR = 7.26; 95% CI: 2.6 - 20.5), and fever (OR = 3.33; 95% CI: 1.1 - 9.8) were associated with a higher risk of CUNP. On the other hand, some features, such as a recent history of febrile illness (presence of fever or body temperature above 38°C in the last month) (OR = 0.36; 95% CI: 0.16 - 0.8) and hyporeflexia (P < 0.01), were associated with a lower risk of CUNP. Conclusion: Acute post-infectious cerebellar ataxia was the most common diagnosis of AA in children, undergoing neuroimaging studies in our center. Nevertheless, tumor was the most common pathology detected on the images of patients with CUNP. Some pathologies might not be detected by some imaging modalities. Considering the associations identified in this study, patients with risk factors, such as a longer duration of symptoms, ophthalmoplegia, focal neurologic deficit, and fever, need to undergo another imaging modality with higher sensitivity if there are no positive findings in the initial imaging study. On the other hand, patients with protective factors, such as hyporeflexia and a recent history of febrile illness, could benefit more from other diagnostic modalities.

ACR Appropriateness Criteria® Ataxia-Child

Childhood ataxia may be due to multifactorial causes of impairment in the coordination of movement and balance. Acutely presenting ataxia in children may be due to infectious, inflammatory, toxic, ischemic, or traumatic etiology. Intermittent or episodic ataxia in children may be manifestations of migraine, benign positional vertigo, or intermittent metabolic disorders. Nonprogressive childhood ataxia suggests a congenital brain malformation or early prenatal or perinatal brain injury, and progressive childhood ataxia indicates inherited causes or acquired posterior fossa lesions that result in gradual cerebellar dysfunction. CT and MRI of the central nervous system are the usual modalities used in imaging children presenting with ataxia, based on the clinical presentation. This document provides initial imaging guidelines for a child presenting with acute ataxia with or without a history of recent trauma, recurrent ataxia with interval normal neurological examination, chronic progressive ataxia, and chronic nonprogressive ataxia. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

The National Italian Guidelines on the diagnosis and treatment of children with pediatric ataxias

Background

Ataxia is a rare neurological condition causing a deficit in the coordination of motor activities, preventing the fluidity of movements. Children with ataxia may show several different ataxic signs, along with difficulties in walking autonomously and ataxic gait often associated with trunk instability. Ataxic signs can be either acute or chronic, and in either case, the diagnosis can be extremely complex. Symptoms and their etiology are often widely heterogeneous, even within the same condition.

Methods

The guideline was developed based on the methodology defined by the Methodological Handbook of the Italian National Guideline System (SNLG) and was reported following the AGREE-II checklist. The SNLG methodology required the adoption of the GRADE approach for the whole development process. To facilitate the implementation of the contents and recommendations from the guideline, two care pathways were developed based on the NICE and the European Pathway Association (EPA) models.

Results

The guideline included 28 clinical questions, 4 on the identification and management of acute ataxias, and 24 on the diagnosis and management of chronic ataxias. The document included 44 recommendations, 37 clinical recommendations, and 7 recommendations for research.

Conclusion

The working group, despite the lack and methodological limitations of the evidence, deemed as essential to provide indications and recommendations, in particular in some clinically relevant areas. The care pathway was produced as a tool to facilitate the implementation of the contents and recommendations. The interactive version of the pathway is available on the SNLG website along with a leaflet dedicated to families and caregivers.

Treatable Ataxias: How to Find the Needle in the Haystack?

Treatable ataxias are a group of ataxic disorders with specific treatments. These disorders include genetic and metabolic disorders, immune-mediated ataxic disorders, and ataxic disorders associated with infectious and parainfectious etiology, vascular causes, toxins and chemicals, and endocrinopathies. This review provides a comprehensive overview of different treatable ataxias. The major metabolic and genetic treatable ataxic disorders include ataxia with vitamin E deficiency, abetalipoproteinemia, cerebrotendinous xanthomatosis, Niemann-Pick disease type C, autosomal recessive cerebellar ataxia due to coenzyme Q10 deficiency, glucose transporter type 1 deficiency, and episodic ataxia type 2. The treatment of these disorders includes the replacement of deficient cofactors and vitamins, dietary modifications, and other specific treatments. Treatable ataxias with immune-mediated etiologies include gluten ataxia, anti-glutamic acid decarboxylase antibody-associated ataxia, steroid-responsive encephalopathy associated with autoimmune thyroiditis, Miller-Fisher syndrome, multiple sclerosis, and paraneoplastic cerebellar degeneration. Although dietary modification with a gluten-free diet is adequate in gluten ataxia, other autoimmune ataxias are managed by short-course steroids, plasma exchange, or immunomodulation. For autoimmune ataxias secondary to malignancy, treatment of tumor can reduce ataxic symptoms. Chronic alcohol consumption, antiepileptics, anticancer drugs, exposure to insecticides, heavy metals, and recreational drugs are potentially avoidable and treatable causes of ataxia. Infective and parainfectious causes of cerebellar ataxias include acute cerebellitis, postinfectious ataxia, Whipple's disease, meningoencephalitis, and progressive multifocal leukoencephalopathy. These disorders are treated with steroids and antibiotics. Recognizing treatable disorders is of paramount importance when dealing with ataxias given that early treatment can prevent permanent neurological sequelae.

Neuroimaging in cerebellar ataxia in childhood: A review

Ataxia is one of the most common pediatric movement disorders and can be caused by a large number of congenital and acquired diseases affecting the cerebellum or the vestibular or sensory system. It is mainly characterized by gait abnormalities, dysmetria, intention tremor, dysdiadochokinesia, dysarthria, and nystagmus. In young children, ataxia may manifest as the inability or refusal to walk. The diagnostic approach begins with a careful clinical history including the temporal evolution of ataxia and the inquiry of additional symptoms, is followed by a meticulous physical examination, and, depending on the results, is complemented by laboratory assays, electroencephalography, nerve conduction velocity, lumbar puncture, toxicology screening, genetic testing, and neuroimaging. Neuroimaging plays a pivotal role in either providing the final diagnosis, narrowing the differential diagnosis, or planning targeted further workup. In this review, we will focus on the most common form of ataxia in childhood, cerebellar ataxia (CA). We will discuss and summarize the neuroimaging findings of either the most common or the most important causes of CA in childhood or present causes of pediatric CA with pathognomonic findings on MRI. The various pediatric CAs will be categorized and presented according to (a) the cause of ataxia (acquired/disruptive vs. inherited/genetic) and (b) the temporal evolution of symptoms (acute/subacute, chronic, progressive, nonprogressive, and recurrent). In addition, several illustrative cases with their key imaging findings will be presented.

Clinical Reasoning: An 8-Year-Old With Acute Onset Ataxia

Acute ataxia is a common neurologic presentation in the pediatric population that carries a broad differential diagnosis. The tempo of the presentation, distribution of the ataxia (focal or diffuse), exam findings, and paraclinical testing may be helpful in guiding diagnosis and management. While Guillain-Barré Syndrome (GBS), and its variant, Miller Fisher Syndrome (MFS), are well defined, frequently encountered acute autoimmune neuropathies, the GBS/MFS spectrum has at least twelve different phenotypes with distinct neurological features, four of which include ataxia. These lesser-known variants can be diagnosed clinically, in the absence of conclusive laboratory or neuroimaging data, and should always be considered in an acute presentation of ataxia. In this manuscript, we present a previously healthy 8-year-old with acute onset ataxia with associated hyporeflexia that occurred after resolution of a presumed viral infection. We discuss our approach to ataxia, the patient’s neurodiagnostic odyssey, and highlight the final diagnosis of acute ataxic neuropathy without ophthalmoplegia - a rare incomplete MFS subtype. Due to timely recognition of the condition, the patient was treated appropriately and recovered fully.

Assessing Children with Poor Coordination Can Be Tricky - A Review on Ataxia and Ataxia Mimickers and a Study of Three Children with Severe Epilepsy

While ataxia is a relatively common presenting feature in pediatric patients, it represents only one possible cause of uncoordinated movements. Other possible causes of uncoordinated movements include ingestion of toxic substances, musculoskeletal diseases, psychogenic disorders, extrapyramidal movement disorders, peripheral neuropathies, spasticity from any cause, and epilepsy. Therefore, primary health care providers must recognize and exclude other etiologies of uncoordinated movements before attaching the label “ataxia” to any patient presenting with poor coordination. Once the presence of ataxia is confirmed, the cause should be investigated. As ataxia may be vestibular, sensory, or cerebellar in origin, medical practitioners must evaluate the diverse symptoms and signs to effectively differentiate the various types of ataxia. Three case studies are presented to illustrate the complexity associated with the assessment of ataxia. Each case will discuss a pediatric patient who displays cerebellar ataxia as a concurrent feature of a gene-specific developmental and epileptic encephalopathy. These cases will provide an example of how ataxia may be differentiated from other causes of uncoordinated movements related to epilepsy and anti-seizure medications, namely: nonconvulsive seizures, postictal state, and medication side effects or toxicity. The assessment of poor balance can be challenging at times; however, with knowledge of the differential diagnosis of poor balance, medical practitioners will be able to confidently determine the presence of true ataxia from various ataxia mimickers, thereby allowing for timely and accurate diagnosis, and appropriate management.

To be, or not to be… Guillain-Barré Syndrome

Guillain-Barré Syndrome (GBS) is currently the most frequent cause of acute flaccid paralysis on a global scale, being an autoimmune disorder wherein demyelination of the peripheral nerves occurs. Its main clinical features are a symmetrical ascending muscle weakness with reduced osteotendinous reflexes and variable sensory involvement. GBS most commonly occurs after an infection, especially viral (including COVID-19), but may also transpire after immunization with certain vaccines or in the development of specific malignancies. Immunoglobulins, plasmapheresis, and glucocorticoids represent the principal treatment modalities, however patients with severe disease progression may require supportive therapy in an intensive care unit. Due to its symptomology, which overlaps with numerous neurological and infectious illnesses, the diagnosis of GBS may often be misattributed to pathologies that are essentially different from this syndrome. Moreover, many of these require specific treatment methods distinct to those recommended for GBS, in lack of which the prognosis of the patient is drastically affected. Such diseases include exposure to toxins either environmental or foodborne, central nervous system infections, metabolic or serum ion alterations, demyelinating pathologies, or even conditions amenable to neurosurgical intervention. This extensive narrative review aims to systematically and comprehensively tackle the most notable and challenging differential diagnoses of GBS, emphasizing on the clinical discrepancies between the diseases, the appropriate paraclinical investigations, and suitable management indications.

Risk factors for the occurrence and recurrence of acute cerebellar ataxia: a retrospective observational study

OBJECTIVE

There is little evidence to support a correlation between abdominal surgery and acute cerebellar ataxia (ACA). We reviewed the records of children with ACA treated at our institution to analyze risk factors for ACA.

METHODS

Clinical data of 442 children with ACA treated at Children's Hospital of Nanjing Medical University between November 2015 and June 2019 were retrospectively analyzed. Univariate and multivariate analyses were performed to determine risk factors for the occurrence and recurrence of ACA.

RESULTS

In total, 442 children with ACA were included in this study. Multivariate logistic regression analysis showed age (p = 0.009), infection (p < 0.001), vaccination (p < 0.001), head trauma (p < 0.001), intussusception surgery (IS) (p < 0.001), operation for indirect inguinal hernia (p < 0.001), and operation for congenital gastrointestinal malformation (p < 0.001) were independent risk factors for ACA occurrence. Univariate analysis showed that only IS (p < 0.001) was associated with ACA recurrence.

CONCLUSIONS

Surgeons should be aware that age, infection, vaccination, head trauma, and history of abdominal surgery are associated with ACA, while IS is a risk factor for ACA recurrence.

Investigating ataxia in childhood

Ataxia is a common presentation to an acute paediatric unit and it can often be difficult to determine the cause. It is important to distinguish between serious causes, for example, brain tumours and encephalitis, and more benign causes in order to guide investigations and treatment. In this review, we describe the different types of ataxia, the causes associated with them, the examination findings and what investigations to perform in order to make a diagnosis.

Acute cerebellar ataxia: differential diagnosis and clinical approach

Cerebellar ataxia is a common finding in neurological practice and has a wide variety of causes, ranging from the chronic and slowly-progressive cerebellar degenerations to the acute cerebellar lesions due to infarction, edema and hemorrhage, configuring a true neurological emergency. Acute cerebellar ataxia is a syndrome that occurs in less than 72 hours, in previously healthy subjects. Acute ataxia usually results in hospitalization and extensive laboratory investigation. Clinicians are often faced with decisions on the extent and timing of the initial screening tests, particularly to detect treatable causes. The main group of diseases that may cause acute ataxias discussed in this article are: stroke, infectious, toxic, immune-mediated, paraneoplastic, vitamin deficiency, structural lesions and metabolic diseases. This review focuses on the etiologic and diagnostic considerations for acute ataxia.

Intestinal Surgery Contributes to Acute Cerebellar Ataxia Through Gut Brain Axis

Introduction: Acute cerebellar ataxia (ACA) is the most common form of pediatric ataxia. Changes in gut flora can modulate the nervous system, influencing brain function via the gut-brain axis (GBA). This study aimed to illustrate the relationship between intestinal microbiota and ACA.

Method: A total of 30 and 12 children were randomly sampled from history of intestinal surgery (HOIS) and no intestinal surgery groups (NHOIS), respectively. In addition, 10 healthy children who sought physical examination in Children's Hospital of Nanjing Medical University were recruited as a control group. The stool samples were 16S rRNA detected.

Results: We observed that many ACA children had intestinal surgery history prior to the onset of ACA. The 16S rRNA sequencing indicated that HOIS and control groups were well-distinguished by principal component analysis. The discrepancy between HOIS and NHOIS groups were also displayed by principal component analysis score plot. However, no differences were found between NHOIS and control groups. The results of student's t-test were consistent with principal component analysis. A total of nine different genera were identified between HOIS and control groups. Five genera and a phylum showed significant differences between HOIS and NHOIS groups.

Conclusion: Altered genera and phyla associated with ACA were identified. Our findings provide new insight into treating and preventing ACA.

Acute ataxia in paediatric emergency departments: a multicentre Italian study

OBJECTIVES

To evaluate the causes and management of acute ataxia (AA) in the paediatric emergency setting and to identify clinical features predictive of an underlying clinically urgent neurological pathology (CUNP).

STUDY DESIGN

This is a retrospective medical chart analysis of children (1-18 years) attending to 11 paediatric emergency departments (EDs) for AA in an 8-year period. A logistic regression model was applied to identify clinical risk factors for CUNP.

RESULTS

509 patients (mean age 5.8 years) were included (0.021% of all ED attendances). The most common cause of AA was acute postinfectious cerebellar ataxia (APCA, 33.6%). Brain tumours were the second most common cause (11.2%), followed by migraine-related disorders (9%). Nine out of the 14 variables tested showed an OR >1. Among them, meningeal and focal neurological signs, hyporeflexia and ophthalmoplegia were significantly associated with a higher risk of CUNP (OR=3-7.7, p<0.05). Similarly, the odds of an underlying CUNP were increased by 51% by each day from onset of ataxia (OR=1.5, CI 1.1 to 1.2). Conversely, a history of varicella-zoster virus infection and vertigo resulted in a significantly lower risk of CUNP (OR=0.1 and OR=0.5, respectively; p<0.05).

CONCLUSIONS

The most frequent cause of AA is APCA, but CUNPs account for over a third of cases. Focal and meningeal signs, hyporeflexia and ophthalmoplegia, as well as longer duration of symptoms, are the most consistent 'red flags' of a severe underlying pathology. Other features with less robust association with CUNP, such as seizures or consciousness impairment, should be seriously taken into account during AA evaluation.

Acute ataxia in children: Common causes and yield of diagnostic work-up in the era of varicella vaccination

We aimed to identify the most common causes of acute ataxia in children in the era of widespread varicella vaccination and the yield of commonly used diagnostic work-up. This retrospective study reviewed the medical records of children who presented with ataxia of less than 72 h duration, over the last 12 years. Associated signs and symptoms, laboratory, EEG and neuroimaging studies, final diagnosis and clinical findings at discharge and during follow-up were studied. A total of 58 patients (35 boys, 23 girls), mean age 4.9 ± 3.8 years, were enrolled. The most common etiology of acute ataxia in our study was post-infectious acute cerebellar ataxia (50%). Children diagnosed with post-infectious acute cerebellar ataxia were significantly younger (3.48 ± 2.23 vs. 6.5 ± 3.1 years, p = 0.01), as compared with children diagnosed with infection and acute disseminated encephalomyelitis. 86% of children with post-infectious cerebellar ataxia were younger than 5 years of age. The abnormality yield of work-up studies performed in our cohort was 39% for lumbar puncture, 36% for EEG, 7% for CT scan. MRI was done in children who showed extra cerebellar signs, when vascular or demyelinating diseases were suspected and in children with prolonged symptoms and was abnormal in 8 (14%) children. We conclude that post-infectious acute cerebellar ataxia remains the most common cause of acute ataxia in children. Although lumbar puncture and neuroimaging should be considered in all children with acute cerebellar ataxia, younger children with a history of previous viral illness and no extra cerebellar signs and symptoms may benefit from watchful waiting.

From Ataxia to Diagnosis of Askin Tumor - a Case Report

Peripheral primitive neuroectodermal tumors (pPNET) are a group of extremely rare, aggressive, malignant tumors that are most often found in the thorax (Askin tumor), abdomen, pelvis, extremities and less frequently in the head and neck. The most important prognostic factor is the stage of the tumor. Significant progress both in surgery and in neoadjuvant and adjuvant chemotherapy and radiotherapy, as well as the improvement in diagnosis by cytogenetic and immunohistochemical analysis, should improve the survival rate. We report a case of a 14-year-old girl, with ataxic gait, cardiopulmonary compensated, without respiratory symptoms, who was referred to our hospital for further examination and treatment of newly discovered tumor of the left hemithorax. After a detailed radiological and laboratory investigation, next step was an extensive thoraco-neurosurgical surgery. After histopathological, cytological and molecular analysis, a diagnosis of Askin tumor was made.

A novel mutation in SLC1A3 causes episodic ataxia

Episodic ataxias (EAs) are rare channelopathies characterized by recurrent ataxia and vertigo, having eight subtypes. Mutated genes were found in four of these eight subtypes (EA1, EA2, EA5, and EA6). To date, only four missense mutations in the Solute Carrier Family 1 Member 3 gene (SLC1A3) have been reported to cause EA6. SLC1A3 encodes excitatory amino-acid transporter 1, which is a trimeric transmembrane protein responsible for glutamate transport in the synaptic cleft. In this study, we found a novel missense mutation, c.383T>G (p.Met128Arg) in SLC1A3, in an EA patient by whole-exome sequencing. The modeled structural analysis suggested that p.Met128Arg may affect the hydrophobic transmembrane environment and protein function. Analysis of the pathogenicity of all mutations found in SLC1A3 to date using multiple prediction tools showed some advantage of using the Mendelian Clinically Applicable Pathogenicity (M-CAP) score. Various types of SLC1A3 variants, including nonsense mutations and indels, in the ExAC database suggest that the loss-of-function mechanism by SLC1A3 mutations is unlikely in EA6. The current mutation (p.Med128Arg) presumably has a gain-of-function effect as described in a previous report.

Acute Cerebellar Ataxia Induced by Nivolumab

A 54-year-old woman with adenocarcinoma of the lung and lymph node metastasis experienced nystagmus and cerebellar ataxia 2 weeks after initiating nivolumab therapy. An evaluation for several autoimmune-related antibodies and paraneoplastic syndrome yielded negative results. We eventually diagnosed the patient with nivolumab-induced acute cerebellar ataxia, after excluding other potential conditions. Her ataxic gait and nystagmus resolved shortly after intravenous steroid pulse therapy followed by the administration of decreasing doses of oral steroids. Nivolumab, an immune checkpoint inhibitor, is known to induce various neurological adverse events. However, this is the first report of acute cerebellar ataxia associated with nivolumab treatment.